The evil can consume you in two ways. One is, you look at evil and you find it beautiful. Some people do; they are captivated by the sheer charm of evil. Aren’t the dons in the movies sometimes very charming? In fact, the most charming characters in the movies in the last few decades have been all underworld dons.
Or, you can be so put off by evil, so incited by evil, that you decide to turn evil to avenge evil. That is another way in which the evil overpowers you.